62 
NATURAL HISTORY. [UPPER FLOOR. 
stitute the class Zoophytaria of De Blainville, and are con¬ 
tained in the Table Cases, Nos. 11—16. 
No. 11 (continued). Cuscutaria— Telesto—Cornularia 
-— Clavularia — Tubipora — Corallium— Isis, and part of 
Melitcea. 
No. 12. Melitoea, and part of Gorgonia. 
No. 13. Gorgonia. 
No. 14. Gorgonia—Eunicea, and Funiculina. 
No. 15. Plexaura—Muricea, and Antipathes. 
No. 16. Antipathes—Cirrhipathes—Hyalonema*,(Grtfj/) 
—Virgularia — Pavonarici — Pennatula — Veretillum —- Re - 
nilla — Briareum — Lobularia — Ammothea — Xenia— Nep- 
toea — Anthelia — Alcyonium — Cydonium — Pnlmonellum — 
Massarium —Cliona. 
The sponges resemble the corals of the last family in 
various particulars, but their animal nature is not distinctly 
made out; those found in collections are merely the skele¬ 
tons of the living mass, entirely destitute of the gelatinous 
portion which constitutes the animal, if it be really of that 
nature. Some naturalists have considered these skeletons, 
or Sponges, as analogous to the stems of Antipathes, or 
Black Coral, and consequently the axes of zoophytes; and 
have fancied that, when alive, they were covered, like the 
Antipathes, with a perishable crust, in which they sup¬ 
posed the polypes to be situated. But recent observations'- 
on them in their living state have not verified this theory; 
for they have been found to be entirely destitute of any 
polypi, and mere living masses, covered with a gelatinous 
coat, and absorbing water through the small pores spread 
over their surface, and emitting it by the larger scattered 
holes called oscula; and though the fibres of many of the 
sponges greatly resemble the axes of the Gorgonise, in 
their chemical composition and organic structure, they 
nevertheless cannot be confidently pronounced to belong 
to the animal, rather than to the vegetable kingdom. 
* The axis of this extraordinary production, which Mr. Gray has 
named Hyalonema , or Glass Rope , is formed of numerous transparent 
siliceous fibres, slightly twisted together so as to look like a rope of spun 
glass; the fibres appear to be somewhat similar to the calcareous spicula of 
the Pennatula . These corals are found with their tapering base inserted 
in a sponge, on the coast of Japan. No animal, hitherto discovered, 
except the inhabitant of this curious and beautiful substance, is known to 
secrete pure silica. 
